matlab - Animating a surf plot -

i've been tasked animating 3d helical flux tube in matlab , i'm unsure of how so.

the animation experience i've had plotting 2d trajectories of 9 solar system planetary orbits, used following code (where z 27 column matrix columns ordered in sequence x,y,z 9 times represent 9 planets)

% plot 9 empty plots p = plot3(nan(9), nan(9), nan(9));  k = 1:size(z, 1)     % update of plot objects @ once     set(p, {'xdata'}, num2cell(z(1:k, 1:3:25), 1).', ...            {'ydata'}, num2cell(z(1:k, 2:3:26), 1).', ...            {'zdata'}, num2cell(z(1:k, 3:3:27), 1).')     drawnow end 

so, intuitively, have tried adapt helical flux tube have follows (where x, y , z 21 x 301 matrices , assume @ each time step must surf rows of x,y , z accordingly required time step):

p = surf(nan(21,301), nan(21,301), nan(21,301));  k = 1:size(x,1)     % update of plot objects @ once     set(p, {'xdata'}, num2cell(x(1:k, :), [1 301]), ...            {'ydata'}, num2cell(y(1:k, :), [1 301]), ...            {'zdata'}, num2cell(z(1:k, :), [1 301]))     drawnow end 

however, doing keep getting error

error using matlab.graphics.chart.primitive.surface/set size mismatch in param cell / value cell pair. 

i know i've made silly mistake somewhere, can help? or if i'm going wrong way let me know?!

(nb if helps, in original script plot helical flux tube, code is:)

surf(x,y,z,'facecolor', colour, 'edgecolor',edgecolour,...     'facelighting','gouraud') 

thanks!!

i not 100% sure want try:

for k = 1:size(x,1)     surf(num2cell(x(1:k, :) ,num2cell(y(1:k, :), num2cell(z(1:k, :);     m(i)=getframe; end 

and display movie afterwards by:

numberofrepitions=3 % want have play in row movie(m,numberofrepetitions) 

maybe easier displayed on random data didnt provide any:

x=[1 2 3; 2 3 4; 3 4 5]; y=[19 17 15; 13 11 9; 7 5 3]; z=[1 1 2; 2 1 1; 3 3 3];  i=1:10     surf(x,y,z);      m(i)=getframe;     x=x+10;     y=y+20;     z=z+25; end  movie(m,3) 

the form of created plot doesnt change can see axis moving, guess work way varying form of surface triangulation.